Targeting public health intervention strategies proceeds best with a clear understanding of the burden of disease and the associated factors that mediate this disease within a population. The disease that we are studying is stroke: the nation's number one cause of disability and third leading cause of death. The population we are studying is Mexican Americans: the overwhelming largest component of Hispanic Americans, the nation's largest minority population. The Brain Attack Surveillance In Corpus Christi (BASIC) Project began rigorous, population-based stroke surveillance in southeastern Texas in January 2000. Recruitment of study subjects has progressed far ahead of schedule. The tremendous collaboration among community, local Public Health Department and investigators has enabled complete ascertainment of stroke cases and detailed procedures to confirm their diagnosis. The BASIC Project aims to provide information to the scientific and public health community regarding stroke in Mexican Americans in two complementary areas. The first objective is to provide accurate rates of transient ischemic attack, first ever and total ischemic stroke, intercerebral hemorrhage and subarachnoid hemorrhage. The relative burden of these diseases in Mexican Americans and non-Hispanic whites will be determined in the fastidious manner that can only occur in a population-based study. The second aspect of the project is to delve deeply into the relationships of access to care, acculturation, stroke risk factors and social determinants of health as these factors interact with ethnicity in their association with stroke. We are confident that our efforts in these two approaches to health disparities will yield critical information that will form a foundation for scientists in the future to reduce race/ethnic health disparities. The Mexican American population is growing and aging quickly. The physical and emotional burden from stroke to this population will grow exponentially over the next few decades. Consequently, the economic burden for stroke will mount for all taxpayers. The BASIC Project reflects years of planning, pilot work, and now detailed, hands-on experience in fostering community relations, collaboration, data acquisition, and analysis. This project began running right out of the blocks and we are in the middle of our sprint. Renewal of this project for an additional five years will enable us to complete the mission we have begun. We will accomplish this with the highest scientific integrity and provide the rich data that people around the country who have seen our project grow have come to expect.